The invention relates to an arrangement for the contactless inductive transmission of electrical measured quantities and/or electrical energy between a rotor and a stator, having
at least one rotor coil arranged on the rotor, with at least one winding; PA1 at least one stator coil arranged on the stator, with at least one winding; PA1 whereby PA1 there is a magnetic coupling between the rotor coil and the stator coil. PA1 the conductor that forms the winding of the rotor coil or of the stator coil is locally structured, by means of modifications of shape and/or material, over the entire extent of the winding in such a way that a fluctuation of the magnetic coupling factor results, and in that PA1 the respective angular position and/or the respective angular speed of the rotor can be derived from the resulting fluctuations of the amplitude of a time-modulated or, respectively, frequency-modulated measurement signal, or from the resulting fluctuations of the transmitted energy. PA1 the conductor that forms the winding of the rotor coil or of the stator coil is locally and periodically structured over the entire extent of the winding by means of modifications of shape and/or of material, such that a periodic fluctuation of the magnetic coupling factor results.
The contactless, precise measurement of the emitted moment of torque, and thereby of the mechanical power on rotating shafts, is today one of the most pressing sensor technology problems in energy and automation engineering. The areas of application are in the monitoring and controlling of drives, as well as in optimization of the efficiency of energy conversion apparatuses. From European reference EP-B-0 354 386, a measurement pickup with a capacitive transducer for contactless measurement of torques on rotating shafts is known that, with low manufacturing costs and a small axial space requirement, can acquire the moment transmitted via the shaft, and thereby also the mechanical power, with a precision of less than 1%, and emits an electrical signal proportional to the torque.
For the contactless measurement of the torque, in general coil systems consisting of a rotor coil and a stator coil are provided via which the measurement signal and/or the electrical energy for the sensor or, respectively, the measurement pickup are transmitted. In the corresponding rotating inductive transmission systems, it is known and is technologically obvious to derive a signal for the RPM from the field non-homogeneity in the area of the current feed.
From German reference DE-A-41 16 085, a method is known for cyclically absolute path measurement in a rotating shaft, in which the phase windings of a rotary current synchronous motor that drives the shaft via its rotor are fed with, in addition to the feed voltages that furnish the motor power, a reference signal of a different frequency. The inductance fluctuations at the individual windings, caused by the rotation of the rotor, and the fluctuations caused thereby of the measurement signal amplitude are acquired, are separated from the actual reference signal frequency using standard demodulation and filter means, and from them two sine oscillations phase-displaced by 90.degree. in relation to one another are produced that identify the respective position of the rotor and thus of the shaft. By this means, an additional resolver or similar angular measurement unit to be coupled with the shaft can be saved. However, a simultaneous transmission of the electrical measured quantities of a sensor or measurement pickup arranged on the shaft is not possible with an arrangement of this sort.